Grinding machine



June 18, 1946. s 1v 2,402,454

GRINDING MACHINE Filed May 51, 1944 I /nren/0r I Patented June 18, 1946 GRINDING MACHINE Arthur Scrivener, Birmingham, England Application May 31, 1944, Serial No. 538,121 In Great Britain June 26, 1943 1 Claim. 1

This invention has reference to improvements in grinding machines and may be applied to any known form of grinder of the external cylinder or centreless type.

The object of the invention is to obtain a higher degree of finish on the surface of the work than can be obtained with known methods and apparatus. In order to obtain the highest degree of surface finish on work which has to be ground it is an accepted practice that the minute grooves cut by the particles of abrasive material of the surface of the grinding wheel should be so arranged as to prevent as far as possible any single particle or series of particles of the abrasive cutting the same path on the work. The present invention aims at achieving this object in a relatively simple manner by a particular arrangement and disposition of the setting of the grinding wheel to the longitudinal axis or line of traverse of the work. Ordinarily the path of rotation of the grinding whee1 is located in a plane which is set at 90 to the longitudinal centreline or traversing path of the work.

The present invention comprises a grinding machine wherein the axis of the grinding wheel is located at an inclination to the longitudinal centreline of the workpiece to be operated upon by the said wheel, i. e. the plane in which the grinding wheel rotates is set at an angle, other than 90, with the longitudinal centreline of the workpiece whilst at the same time when observed in a plane at right angles to the aforesaid the axes of the grinding wheel and of the workpiece do not intersect but remain in two planes parallel to each other, the face of the grinding wheel being projected as a concavity which is determined by the angle of incidence obtaining between the plane of rotation of the wheel and the centreline of the workpiece.

An embodiment of the invention will now be described with reference to the accompanying diagram which illustrate an application of the present invention to a grinding machine for centreless grinding wherein is embodied a rotatable grinding wheel, a rotatable control wheel, a longitudinally traversable workpiece and a stationary work support.

Figure 1 is a side elevation looking on the control wheel.

Figure 2 is a front elevation looking from the left hand side of Figure 1,-and Figure 3 is a plan of Figure 2.

The grinding wheel a is set in the machine so that its axi a is at an inclination to the longitudina1 centreline b or traversing path of the workpiece b when viewed in one plane (see Figure 1) but remains parallel when viewed in a plane at right angles thereto (see Figures 2 and 3); ordinarily the axis a and the centreline b have a parallel disposition when viewed in both the horizontal and vertical planes. This inclination of the one axis or path to the other involves that the periphery of the grinding wheel a is formed with a slight concavity which is projected and determined by the angle of incidence obtaining between the axis a of the grinding wheel a and the centreline b or path of traverse of the workpiece b, so that when the machine is in operation the particles of abrasive which form the peripheral surface of the grinding wheel a will continuously cut across new paths on the surface of the workpiece instead of in the same path as normally obtains. Thus what is known as ringing of the work is avoided and a smoother or more uniform surface will be produced on the work, as by this particular setting of the grinding wheel a to the work a new contact is continuously obtained between the periphery of the grinding wheel and the surface of the work which is being ground.

In the illustrated diagrammatic embodiment of the invention there will be seen a rotatable control wheel 0 the axis 0 of which is also inclined relative to the'longitlldinal centreline b of the workpiece, the inclination of the control wheel 0 being shown in Figure 1 at a slightly different angle to that of the angular setting of the grinding wheel a. d is a stationary workpiece support mounted on the frame of the machine.

I claim:

A centreless grinder comprising, in combination, a work support for maintaining the axis of a workpiece substantially fixed, a grinding wheel whose axis is inclined forward out of parallelism with the axis of a workpiece held by the work support, and a control wheel whose axis lie in a plane parallel to both of the aforesaid axes but is inclined forward by a greater angle out of par- 

